The following is from memory (I don't have a materia medica with me), but I'm pretty sure that this is correct.
Mag phos 30x is a homeopathic remedy useful for gas pain that is relieved by curling up into a ball, i.e., a fetal position.
Staphysagria is a homeopathic that is useful for severe gas pain following abdominal surgery (such as cesarean section). You don't mention cesarean section with regard to this client, but just in case . . . .